;
};
Routes the test value into one of several branches based on a check, with an
optional fallback for "none of the above".
Per dated property in the test value, Switch picks the first branch whose
check conforms with the value, or falls through to the fallback. Pair with
Each when downstream branches should iterate inside a list.
### Inputs
* **Test Value** — the dated property (or list of them) to route.
### Outputs
* **Check** — connect one or more nodes whose result decides the branch.
The matched branch always carries the **original test value** onward (with
its `valid_from` intact), not the check node's own output.
* **Fallback** (optional) — taken when no Check conforms. If a value matches
no Check and no Fallback is wired, evaluation fails — a value with nowhere
to go is a misconfiguration, not a silent drop.
* **Empty** — taken when the test input is an empty timeline. Wire a
subgraph here to emit a default value when the upstream has no data.
If unwired, Switch emits an empty timeline directly.
* **Result** — the merged result after routing every dated property.
### How conformity is decided
* *Value* nodes (*Constant*, *Attribute*, *Date Today*, arithmetic, …)
conform when their output **equals** the test value.
* *Date range* checks (a *Constant* typed `date range`, or a *Date Range*
node) conform when the test value falls inside the period — bounds
inclusive, an empty bound meaning open-ended. A range test value conforms
when the two ranges overlap.
* *Predicate* nodes (*Equals*, *Match*, *Greater Than*, *Less Than*, …)
conform when their output is `true`.
* An exact value match wins over a passing predicate. More than one match in
the winning tier is nondeterministic and errors. A check whose subgraph
errors simply doesn't match.
Date-range checks count as value matches, so overlapping ranges on one Switch
are an error rather than a first-one-wins race. Wire the catch-all to
*Fallback* instead of adding a range that covers everything.
## Ports